Tonsil stone: A tiny stone (calculus) in the tonsils.
These stones, called tonsilloliths, are found within little pockets (crypts) in the tonsils that typically form in chronic recurrent tonsillitis and harbor bacteria.
The stones are foul-smelling. They tend to contain high quantities of sulfa. When crushed, they give off the characteristic rotten egg smell which is well known to cause bad breath.
Tonsilloliths may also give the sense of something being caught in the back of the throat.
Also referred to as a tonsillith.